Desulfurizing and smelting ores.



A. S. DWIGHT.

DESULFURIZING AND SMELTING ORES.

APPLICATION FILED JUNE 25, 1908. RENEWED my 12,1913.

1 169,069, Patented Jan. 18, 1916.

" IIVI/ENTOR WEE/8.9

I -52! ATTORNEY ARTHUR swam, or YORK, N. Y.

@FFTGE.

DESIlLFURIZlING Ari '30 siuEL'rINe onus.

Specification of Letters Patent. Patented J an 18, 1916.

Application filed June 25, 1908, Serial No. 440,404. ReniawedMay 12,1913. Serial No. 767,188

companying drawings.

This invention relates to improvements in processes for treating ores, particularly those which are susceptible of a desulfurizing or kindred treatment and a sintering treatment, either simultaneously or successively, and of being subsequently reduced by smelting or similar operation.

The essential parts of the invention can be carried out in apparatus of any of several forms. In the drawings accompanying this description there is shown an apparatus of one of the types that can be used for this purpose.

Figure 1 is a view partly in side elevation, partly in vertlcal section of a mechanlsm which can be so used. Fig. 2 1s a plan view of the same. partly in horizontal section.

Fig. 3 1s a fragmentary section on the line E -3 of Fig. 2.

It will be understood that the apparatus or set of devices presented in the drawings is illustrated more or less conventionally, but in such a way that the essential parts of the process and apparatus may be readily understood by those skilled in the art. Generally considered the process can be regarded as comprising two stages, and the mechanism illustrated for carrying out the proccan be considered as made up of two main parts.

A indicates, as an entirety, the apparatus or set of parts used for primarily receiving the ore, or other materials, distributing it or them in a layer, in a charge or a series of charges, and subjecting it or them to preliminary treatment, whereby such ends are attained as desulfurization and sintering, or the like.

B indicates, as an entirety, a smelting furnace of a form such as to make it available for the next stage of treatment, and having the usual, or any desired adjuncts. In describing the process and apparatus,

one can keep in-mind some of the more commonly found sulfid ores such as copper sulfid, though it is to be understood that the invention is not limited to any particular material. I

The preliminary sintering or agglomerating of the ore can be accomplished as follows: L. indicates a hopper or receptacle for initially receiving the ore or other ma,- terials. From this it is allowed to pass to a carrier or transporting mechanism. As shown, use is made of a series (M) of pans, buckets, or pallets (m) such as are frequently employed in constructing conveyers. Each may be made with a horizontal gratelike part or perforated bottom plate adapted to support the ore, and at the same time allow the passage of air therethrough. It is also preferably provided with rollers M adaptedto travel along a guideway having the upper section N, the lower section N and a connecting part N at the delivery end. 0, 0, indicate lifting and propelling wheels for the pans or buckets. The lower part N of the guide-way has "an upwardly curved section a at the delivery end of the apparatus and an upwardlycurved section 11, passing around the axis of the propelling wheels 0, 0. At P there is an igniting apparatus which may be, of any preferred form, either a gas-pipe perforated to provide a. series of gas jets across the topof the ore mass, or a conductor and burner for oil, or means for supporting any suitable flaming material. The ore as it passes from the hopper L is delivered in a stream or layerof several inches thickness tothe pallets, buckets or pans, as they move in series in the way illustrated. As the ore stream passes under the igniting apparatus at P the combustible elements are ignited. Q indicates an air box from which air can be exhausted and when there is ore upon the carrying apparatus air will be drawn from above the ore mass downward through it into the trunk or box at Q and thence to a place .of discharge. When the pallets, buckets, or pans (m) successively reach the point B their contents are removed from them and they successively return to their initial position as shown at m The contents are conveyed from the point of patents issuedto and applications filed by discharge in any suitable way. One form of device for this is indicated at S, it being a chute, table or guide adapted to take the ore from the carrier and conduct it to the furnace. n

It is not necessary to here describe in detail the actions of the several parts, or the several incidents .to the method of treatment of the mat rial, as the ore passes through this first part of the apparatus. These are fully described in Patent 882,518 and other A. S. Dwight and R. L. Lloyd and the description need not be here repeated in detail. Suflice it to say that the ore moves along on the supporting and transporting until the fire reaches the bottom of the layer.

This occurs at, or nearly at, the moment when the stream has reached the point B. The heat generated by the general combustion causes the ore to sinter or form a rigid coherent porous sheet or layer. After the sintering action is completed the sheet or cake is withdrawn at R as above described, by the chute or table S, the empty pallets or pans returning in the way set forth. The stream or layer of sinter is carried directly into the smelting furnace at B. As shown it passes through an opening (.23) in the wall of the furnace.

The furnace here selected for illustration is of a reverberatory form. It has a hearth at E, the top being indicated by (b). The sinter is delivered to the interior at points above the hearth E,where it is impinged upon by melting flames, preferably flames formed by the ignitionof streams of gas or oil commingled with air and supplied through nozzles D, shown as directed so that their axes converge with the lines of travel of the sinter, though any other means of melting may be employed,such= as electricity, coal burned on a grate, pulverized coal, etc.

Fluxing materials can be combined with the sintered, ore either by introducing them into the smelting furnace, as for example, from hoppers or receptacles K, which are arranged to deliver such fluxing material directly to the surface of the sintered or agglomerated mass after it is completely formed, and just before it is subjected to the smelting operation, or by initially commingling them with the ore during or prior to the desulfurizing and sintering actions, or by feeding the flux into the furnace in contact with the sinter cake. As the sintered ore reaches the region above the hearthE, it is smelted into a metal or matte, while the earthy ingredients separate themselves in 'ously through'the tap hole H, or can be taken matte, being the heavier, is collected in the bottom part of the separator indicated as a whole by F and canbe drawn ofl" continuofl' at-intervals by any well known method. The slag, being lighter, floats on the top of the metal ormatte, being collected in the upper part' of the separating chamber. It can be allowed to escape contmuously through the tap hole G, or can be collected in charges andwithdrawn atinterva'ls;

A description of an the details incide'ntto i the operation of smelting need not be given,

as they will be fully understood by those skilled in the art to which the invention pertains, and it will be also understood that the quantities of air, fluxes, and fuel material (gas, oil, or others) will be regulated or varied to correspond with the character and constituents of the ore-sinter whichis delivered to the furnace in the way above described.

It is preferable, but not essential, that the delivery of the sintered ore to the furnace B should be accomplished as speedily as possible after thetdesulfurizing and sintering actions have been completed as the sinter retains for a period a large amount of the heat which has been generated during the preliminary treatment, and this heat can be economically utilized in the smelting operation.

The principal part of the sinter mass is delivered to the interior of the furnace chamber in the way illustrated in the draw-. ings, that is to say, as a continuously advancing inward-projectingbody moving at a speed proportioned to the smelting capacity. But it will be understood that this is not essential to successful results for if any of the sinter-mass should be delivered in broken pieces they fall but a short distance to reach the hearth where they still remain in the intensely heated region, that is, in the focus of the heat and the smelting is quickly accomplished. The advancing of the end part of the ore mass as an inward extending projection keeps constantly exposed, on nearly all sides, a mass of the orewhich is readily played on by the flame or heat-rays, the latter having access to the mass on its under surface as well as its end and top, and as the material is in a porous condition the metal is easily reached and attacked by the heat, practically all sidesof the-mass at its end being, as aforesaid, subjected to the melting temperature. a

It is not to be understood that all of the features of the invention are to be limited to supplying the sintered ore to the furnace in a continuous stream or streams. It can be delivered in a series of shorter and separated sections or cake-like blocks.

In the earlier practice with reverberatory smelting furnaces it has been customary to intermittently charge the material into the furnace in comparatively large quantities in a pulverulent condition and to depend upon the reverberated heat applied to one side only of the mass, for melting it. And it has been impossible in such earlier practice to obtain the thorough and intimate mixture of all the ingredients of the charge necessary for the most efficient and economical work. But it will be seen that by the method herein described (which provides for intimately commingling, at an initial stage, all the ingredients of the final furnace charge, and maintaining them thus intimately commingled during the sintering stages,) the maximum effect of the heat in the furnace, can be secured as it is applied to the aforesaid intimate mixture in a thoroughly porous mass, constituting a structure in which the silicates of the metallic oxids and earthy bases are already formed and the whole mass is readily attacked by the heat and at a speed exactly equal to the melting capacity of the flame. These ends cannot be obtained where the charge consists of masses of pulverulent material, as they cannot be held in contact with the melting flame long enough to properly melt without mechanical loss incident to the carrying of much of the material into the flues because of its pulverulent character.

The product of the machine A, as has been pointed out, is a rigid sinter cake or agglomerated mass of metal-bearing material, highly and uniformly porous throughout. In this physical condition it is peculiarly well adapted for being smelted, since it presents a very extensive exterior surface besides numerous interior surfaces, all of which are simultaneously subject to the action of the smelting agencies. It is desirable, if this characteristic of the material is to be fully availed of, that the material be fed to the furnace gradually, that is, substantially as fast as it is smelted, but practically no faster, and be there immediately and uniformly acted upon by the smelting agencies; and this is found to be especially advantageous when operating upon mate- 'rials that do not require any treatment to effect chemical changes between the sintering step and the final smelting step, as, for instance, is the case when acting upon sinter formed from copper sulfid ore. This is in contradistinction to processes heretofore in vogue, such for instance as where metalbearing material in finely divided form is fed intermittently to the furnace in relatively large charges. When this takes place in a reverberatory furnace, part of the charge forms a pile or mound,often extending entirely through the molten bath quite to the bottom of the furnace, to which it adheres, as well as above the surface thereof,while other parts float off upon the surface of the bath and form a more or less complete cover or blanket therefor. The result is that the temperature of the furnace is temporarily reduced to a material degree by the. large amount of material entering the furnace at one time, and the said blanket covering the bath operates to prevent the heating agencies acting thereon, so that its temperature is not maintained. .The action of the furnace under such conditions is in regular,its' temperature varying widely from time to time,while the different portions of the charge of material being smelted, are subjected to radically different conditions. These objectionable features are largely or entirely overcome in practising the process herein described. By introducing the sinter material into the free space within the furnace above the extensive exposed surface of the molten bath, it becomes immediatelysurrounded on all sides by the highly heated smelting gases, where such are employed as the smelting agents, and these at the same time act directly upon the bath resulting from the smelting of the sinter, which is thus kept in fluid condition so that the desired Stratification therein quickly and easily takes place.

What I claim is:

1. The herein described process of sintering and smelting ore initially in a fine condition, which consists in continually forming a relatively-thin stream or layer of the ore,

sintering the said stream into a relatively strong and rigid sinter cake at a point relatively remote from the region of smelting, continually moving the cake horizontally away from the region of the forming and sintering, projecting the forward part of the cake into the region of smelting, and subjecting it to smelting action.

2. The herein described process of sintering and smelting ore initially in a fine condition, which consists in continually forming a relatively thin stream or layer of the ore, sintering the said stream into a porous cake at a point relatively remote from the region of smelting, continually moving the porous cake away from the region of forming and sintering, and subjecting the forward part of the said cake to a smelting action.

3. The herein described process of sintering and smelting ore initially in a fine condition, which consists in continually forming a relatively thin stream or layer of the ore, sintering the said stream into a cake at a point relatively remote from the region of smelting, causing a gas to pass through the ore during the process of sintering whereby the resulting sinter cake is made porous, continually moving the sinter cake away from the region of forming and sintering, and subjecting the forward end of the porous cake to the action of a smelting furnace.

, 4. The herein described process-of obtaining metal from ore initially in a fine condition and free of foreign binding material, it consisting infirst forming a layer, cake or block of sinter, then slowly advancing the said block or layer of sinter into a. furnace region and subjecting itto the action of a smelting flame, and gradually advancing it during the smelting action. I

5. The herein described process of obtaining metal from ore initially in a fine condition and free of foreign binding material, it consisting in forming a relatively thin layer or block of sinterand then feeding the sinter edgewise into asmelting region, and subjecting it to the action of smelting flame applied to and around the advancing edge of the sinter.

6. The herein described process of sinter-- ing and smelting ore initially in a fine condition,- which conslsts 1n continually formlng a relatlvely tlnn layer or stream of ore, subjecting the layer or stream to the action of heat, derived independently of the smelting action to cause sintering into a continu s cake, advancing the cake away from th region of action of the said sintering heat, and subjecting the forward end of the cake to the action of a smelting furnace.

7. The herein described process "of obtaining metal from ore initially in a fine condition, it consisting in forming a continuous stream or layer of the fines, sintering the said stream, advancing the sinter while heated from the sintering action and in a continuous unbroken mass to the'interior of a furnace, and subjecting it to a smelting action.

8. The herein described process of sintering and smelting ore'initially in condition of fines adapted to be sintered without the addition of foreign binding material, it consist-,

ing in subjecting the fines to the action of heat derived independently of the smelting process and thereby forming agglomerated masses of sinter, and delivering the sintered masses substantially continually to the interior of a smelting furnace.

9: The herein described process of obtaining metal from ore initially in a fine condi tion, it consisting in forming a relatively thin stream or layer of the fines, sintering the said stream, advancing the resulting sinter cake while heated from the sintering action to the interior of a furnace, and subjecting it to a smelting action.

10. The herein described process of obtaining metal from ore initially in a fine condition and free from foreign binding milf layer toward a smelting furnace from the region of forming, sintering the layer while advancing by the action of heat derived independently of the smelting furnace, and

smelting theforward part of the said layer in the said furnace while retaining the heat of sintering.

. 11. The herein described process of obtaining metal from'ore initially in' a fine ing, and subjecting the forward part of the cake to the action of a smelting furnace.

12. The herein described process of treating ore initially in-a condition of fines adaptedto be sintered and obtaining the metal therefrom, it consisting in moving a mass of the ore in a substantially continuous stream from a region of combustion and'sintering to the interior of a smelting furnace,

simultaneously subjecting one part of the said mass to internal combustion to effect the sintering, and subjecting another part of the mass, after sintering, to the action of smelting flames.

18. 'The'herein described continous process of obtaining metal from ore initially in a fine condition, it consisting in first subjecting a mass of the ore to internal combustlon and smtering it, advancing the sintr to the interior of a smelting furnace,

' exposing theinwardly extending solid sinter to the action of smelting flames in the furnace and collecting the material smelted thereby.

14. The herein described process of obtaining metal from ore initially in fine con+ dition, it consisting in forming a relatively shallow stream of ore, advancing the said stream toward a smelting furnace, subjecting the ore while advancing to interna combustion, sintering it by such combustion, causing the sinter to project into the smelting region, and subjecting it to the action of the smelting flame.

15. The herein described process of obtaining metal from ore initially in a finecondition and containing combustible ingredients, which consists in continually forming a layer of the ore containing the said combustible ingredients, subjecting the layer to internal combustion to cause it to be sintered into a cake, continually moving the cake away from the region of forming and sintering, and subjecting the forward part of the cake to a smelting action while .itretains the heat of sintering.

16. The herein described process of ob-' taining metal from ore initially in a fine condition and containing combustible ingredients, which consists in continually forming a layer of the ore containing the said combustible ingredients, subjecting the ore to internal combustion to cause sinter ing, passing an aeriform gas through the layer of ore during sintering to support combustion and to insure porosity of the resulting sinter cake, contmually movlng the cake away from the region of forming and slntermote from the furnace to-the action of heat derived independently of the furnace, causing the continued movement of the layer away from the region of heating, and subjecting the forward end of the said layer to a smelting action in the furnace while retaining the heat of the before mentioned action.

18. The herein described process of sin- 1 tering and smelting ores initiallyin a fine condition and adapted to be sintered with out the addition of foreign material, which consists in continually'for ning a layer of the ore, moving the said layer away from the region of forming toward a smelting furnace, subjecting the layer at a point remote from the furnace to the action of heat I derived independently of the furnace, causing the continued movement of the layer away from the region ofheating, and subjecting the forwardend of the said layer to a smelting action in thefurnace while retaining the heat of the before mentioned action. I

19. An apparatus for ore treatment comprising a continually moving element, means for depositing a continuous layer of ore on the said element, means for subjecting the said layer of oreto a sintering action to form a continuous cake, and means for continually smelting the forward end of the said'cake as the cake is advanced by the An apparatus for ore treatment comprislng a continuallyv moving element, a means for depositing a continuous stream of ore on the element, a means for causing the sintering of the said one by the action of heat into a continuous cake, and means for continually smelting the forward end of the said advancing cake while the cake retains the heat of sintering.

21. An apparatus for ore treatment comprising a means for continually forming a continuous cakeof sintered ore, a moving platform for continually advancing the said of molten material resulting from the cake, and means for continually smelting the forward end of the said advancing cake. a

22. An apparatus for ore treatment comprising a means for continually forming a continuous cake of sintered ore, a moving platform for advancing the cake, and a furnace having an aperture adapted to receilye the forward end of the said advancing ca e. V V

23. The herein described process of obtaining the metal from metal-bearing material that is initially in a finely subdivided condition, which consists in first agglomerating such material into rigid masses, that are highly and uniformly porous throughout, and then introducing such masses into a smelting furnace gradually and substantially as fast as the smelting takes place, and subjecting them immediately upon their introduction into the furnace to the direct and uniform action of smelting agencies.

24. The herein described process of obtaining the metal from metal-bearing material that is initially in a finely subdivided condition, which consists in first agglomerating such material into rigid masses that are highly and uniformly porous throughout, introducing such masses into a smelting furnace in which is maintained a bath smelting of said masses where a separation of the metallic from the other component parts thereof takes place and having an extensive exposed surface, and there being a free open space above the said surface of the molten .bath, the introduction of the material being gradual and substantially as fast as the smelting takes place, and into the said open space above the level of the molten bath, and there, subjectingit immediately upon its introduction to the direct and uniform action of smelting agencies.

25. The herein described process which consists in forming fine metal-bearing material into rigid masses in sheet form and Y that are highly and uniformly porous throughout, and permeable to gases, ap plying to the surface of such masses .after being formed and while in sheet form a, fluxing material and then delivering said masses and the fluxing material to a smelting furnace and there subjecting them to the action of smelting agencies.

In testimony whereof I, the said ARTHUR S. DWIGHT, hereto aflix my signature, in presence of two witnesses.

' ARTHUR S. DWIGHT. Witnesses:

L, GRACE ELIZABETH SEfMoUR,

GEORGE R. BLISS. 

